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Updated: Jul 20, 2026

Behavioral Characterization of Pentylenetetrazole-induced Seizures: Moving Beyond the Racine Scale
Published on: July 8, 2025
[A young woman with a labile mood, hyperactivity, hyperthermia and exhaustion: symptoms of lethal catatonia]
I M K ter Haar1, R J Rutgers, P H M Egbers
1GGZ Zuidwest-Friesland, Sneek.
A 22-year-old woman went through a period with a labile mood that first turned into psychotic hyperactivity and was then followed by hyperthermia and exhaustion. This was accompanied by diminished consciousness, sinus arrhythmia and respiratory insufficiency. With a working diagnosis of 'lethal catatonia' she was treated by electroshock and later also with the antipsychotic agent quetiapine. After a few electroshock treatments her vital functions improved and ultimately, the patient recovered. Lethal catatonia is characterised by acute excitation, catalepsy, autonomic instability and fever, which can lead to death. The syndrome often starts with mood instability, which turns into hyperactivity accompanied by hyperthermia and exhaustion. The creatine kinase, blood-sedimentation rate and leukocyte count are often raised. Lethal catatonia must be distinguished from the neuroleptic malignant syndrome, serotonin syndrome and encephalitis. The pathophysiology is unclear, but most reports suggest a hypodopaminergic state. The syndrome is associated with affective disorders and schizophrenia. Early recognition is made difficult by the low frequency of appearance, diversity in nomenclature, and strong resemblance to other syndromes.
A 22-year-old woman went through a period with a labile mood that first turned into psychotic hyperactivity and was then followed by hyperthermia and exhaustion. This was accompanied by diminished consciousness, sinus arrhythmia and respiratory insufficiency. With a working diagnosis of 'lethal catatonia' she was treated by electroshock and later also with the antipsychotic agent quetiapine. After a few electroshock treatments her vital functions improved and ultimately, the patient recovered. Lethal catatonia is characterised by acute excitation, catalepsy, autonomic instability and fever, which can lead to death. The syndrome often starts with mood instability, which turns into hyperactivity accompanied by hyperthermia and exhaustion. The creatine kinase, blood-sedimentation rate and leukocyte count are often raised. Lethal catatonia must be distinguished from the neuroleptic malignant syndrome, serotonin syndrome and encephalitis. The pathophysiology is unclear, but most reports suggest a hypodopaminergic state. The syndrome is associated with affective disorders and schizophrenia. Early recognition is made difficult by the low frequency of appearance, diversity in nomenclature, and strong resemblance to other syndromes.
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